Systems for monitoring physiological variables on a daily basis at point-of-care (POC) are deemed as the cornerstone technology for improved health care delivery at reduced costs. ELISA and other laboratory techniques such as high performance liquid chromatography, surface plasma resonance, and equilibrium dialysis are the prevailing methods for monitoring physiological variables in the current state of the art. Most of these techniques do not lend themselves well to miniaturized automated systems for application at POC.
Therefore, POC systems that can quantify critical physiological parameters can enable better diagnosis and better treatment strategies. Many of the current sensing systems that are used in diagnostic laboratories cannot be applied at POC due to constraints of portability, cost, analysis time, and requirement of highly skilled personnel to operate these systems. Microfluidic systems have enabled the development of POC chemical and biological assays. The main advantages of microfluidic systems are small sample volumes, precise control of fluidic routines, repeatable sensing protocols, controlled environment for bio-molecule reaction, reduced form factor, and application at point of care. The high degree of automation that exists in microfluidic systems also eliminates error often associated with human handling and thereby reduces the percentage of inaccurate results.